Study on a new type of sealing - regeneration-labyrinth sealing for displacer in cryocoolers: Part I - Theoretical study

A new concept of sealing structure - regeneration-labyrinth sealing has bee n put forward to substitute for sealing rings that influence seriously the performance of cryocoolers. A program, which can simulate the thermophysica l process occurring in the sealing structure, is developed consequently. Us ing numerical simulation, the reasonable structure of the regeneration-laby rinth sealing has been determined. The influences of some parameters, such as the heat transfer coefficient of forced convection, the cylinder-displac er gap, the diameter and length of cylinder on the losses of cooling capaci ty have been studied numerically. As a result, the designing principle of t he new type of sealing is obtained. (C) 2000 Elsevier Science Ltd. All righ ts reserved.